Computer system with blade system and management server

ABSTRACT

Provided is a computer system in which power consumption of the system can be reduced and which can smoothly supply data for a request from a client and avoid increase in a failure rate. In the computer system, by maintaining a power activation threshold for activating a stopping server blade and load balance threshold for assigning the request to a server blade, a server blade whose power is activated but to which the request from the client is not assigned is previously arranged. Priorities of the server blades are maintained, and are periodically changed or are changed in accordance with operation information such as total operation time and the number of times of activation/stop. Further, by maintaining the power activation threshold and a power stop threshold, possibilities of the unbalance among the activated/stopped server blades and frequent control of the activation/stop only in a part of server blades are avoided.

TECHNICAL FIELD

The present invention relates to a computer system configured with amanagement server and a blade system having a plurality of serverblades, and more particularly, the present invention relates tooperation control for a blade system in which reduction of powerconsumption of the system is achieved with performing load balance(distribution).

BACKGROUND ART

Recently, a server system as aiming at data acquisition by theconnection from a client to a server via a network has been widely used.A typical one is the Internet access mode.

Recently, as these server systems, a blade system including a pluralityof server blades has been used often.

Also, as aiming at handling rapid increase in the access or keepingfault tolerance, a request from the client is balanced (distributed) foreach server blade for processing often. A device for the distributionprocessing is called a load balancer.

In the load balance, for each server blade configuring the blade system,a method of uniformly balancing the load is generally used.

For example, methods such as “the minimum access mode” which selects aserver blade having the smallest number of connections from/to theclient and “the fastest response mode” which selects a server bladehaving the shortest response time for the request are used often.

However, in this case, in spite of a processable method by a smallnumber of server blades when performances of the server blades are high,it is required to activate all server blades regardless of theirprocessing amounts. Therefore, there is a possibility that powerconsumption of entire system is increased.

Accordingly, as a new method against the general load-balancing methods,the one disclosed in, for example, Japanese Patent Application Laid-OpenPublication No. 2003-281008 (Patent Document 1) is cited.

The one disclosed in Patent Document 1 distributes the request from theclient preferentially to a server having the shortest operation time,and besides, can start up only the least required servers for the entireserver system by comparing a data request amount from the client with adata supply possible amount.

Patent Document 1: Japanese Patent Application Laid-Open Publication No.2003-281008

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, conventional techniques including the one of theabove-described Patent Document 1 have the following two problems.

As a first problem, a situation of increase in the request from theclient is considered.

Here, in the technique described in Patent Document 1, the number ofoperating servers is optimized by comparing the data request amount fromthe client with the data supply possible amount of a group of theoperating servers, so that a stopping server is power-activated.

In this case, a certain time is required from the start of the serveractivation through the receiving of the request from the client to thestart of processing. Therefore, when the processing from the client israpidly increased, assignment for the processing to the server may bedelayed.

As a second problem, in the technique described in Patent Document 1,activated and stopped servers are determined based on power consumed bythe server, and therefore, there is a possibility that unbalance amongthe activated and stopped servers may be caused in only a part ofservers.

Also, when a situation that increase and decrease in the request fromthe client are repeated within a narrow range is taken intoconsideration, if the narrow range is a range judged as a request ofadditional server activation, there is a possibility that a part ofservers may be intensively activated and stopped for short time.

As characteristics of electric and electronic equipment, heat expansionis caused due to temperature increase at the power activation, andshrinkage is contrarily caused due to temperature decrease at the powerstop.

As a result, a substrate, each element, solder, and others are easilydeteriorated, and easily broken. That is, when the activation and stopare intensively controlled in the part of servers, there is a highpossibility that the servers are broken.

Accordingly, a preferred aim of the present invention is to provide acomputer system capable of reduction of power consumption of the system,and besides, capable of achieving smooth data supply for the requestfrom the client and avoiding increase in a failure rate.

The above and other preferred aims and novel characteristics of thepresent invention will be apparent from the description of the presentspecification and the accompanying drawings.

Means for Solving the Problems

The typical ones of the inventions disclosed in the present applicationwill be briefly described as follows.

That is, as a summary of the typical one, a blade system and amanagement server are provided, the blade server including: a prioritymaintaining unit for maintaining a priority set in each of a pluralityof server blades; a load-balance-threshold maintaining unit formaintaining a load balance threshold for balancing a processing amountof each of the plurality of server blade; and a load balancing blade forassigning a processing of a request from a client preferentially to aserver blade having a higher priority among a plurality of operatingserver blades, and a management server including: a judgment table forstoring information from a monitoring unit for server-blade operationstatus; a maintaining unit for a power activation threshold formaintaining the power activation threshold for activating the pluralityof server blades; a maintaining unit for a power stop threshold formaintaining the power stop threshold for stopping the plurality ofserver blades; and a judging unit for judging activation or stop of theplurality of server blades based on the information of the judgmenttable, the power activation threshold, and the power stop threshold tocontrol a power controlling unit. The judging unit stops a server bladeto which the processing of the request is not assigned by the loadbalancing blade among the plurality of server blades.

Effects of the Invention

The effects obtained by typical aspects of the present invention will bebriefly described below.

That is, as the effects obtained by typical aspects, in a computersystem including a blade system with a load-balancing function, powerconsumption can be reduced.

In addition, by setting a power activation threshold and a load balancethreshold for each server blade or setting the maximum number ofstand-by server blades and the minimum number of stand-by server blades,data can be rapidly supplied when the request from the client is rapidlyincreased. Also, by changing a priority of each server blade, settingthe power activation threshold and the load balance threshold, orsetting the maximum number of stand-by server blades and the minimumnumber of stand-by server blades, unbalance among the activated/stoppedserver blades is decreased, so that a failure rate of the blade systemcan be decreased.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a configuration diagram illustrating a configuration of acomputer system according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a judgment table used in a selectionprocessing for activated/stopped server blades of the computer systemaccording to the embodiment of the present invention;

FIG. 3 is a flowchart illustrating the selection processing for theactivated/stopped server blades of the computer system according to theembodiment of the present invention;

FIG. 4 is another flowchart illustrating the selection processing forthe activated/stopped server blades of the computer system according tothe embodiment of the present invention;

FIG. 5 is an explanatory diagram for explaining change of a priority ofthe computer system according to the embodiment of the presentinvention;

FIG. 6 is another explanatory diagram for explaining change of thepriority of the computer system according to the embodiment of thepresent invention; and

FIG. 7 is still another explanatory diagram for explaining change of thepriority of the computer system according to the embodiment of thepresent invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings. Note that componentshaving the same function are denoted by the same reference symbolsthroughout the drawings for describing the embodiment, and therepetitive description thereof will be omitted.

With reference to FIG. 1, a configuration of a computer system accordingto an embodiment of the present invention is described. FIG. 1 is aconfiguration diagram illustrating the configuration of the computersystem according to the embodiment of the present invention.

In FIG. 1, the computer system includes: a blade system 180; and amanagement server 190 for managing an operation of the blade system andcontrolling the operation.

The blade system 180 includes: server blades 130 to 132 for processing arequest from a client 100; a load balancing blade 120 for assigning therequest from the client 100 to each of the server blades 130 to 132; anda power controlling unit 140 for commanding activation or stop to eachof the server blades 130 to 132 in accordance with an instruction fromthe management server 190.

The load balancing blade 120 includes: a data-request receiving unit121; a data-request transferring unit 122; a server-blade monitoringunit 123; a load-balance-threshold maintaining unit 124; and a prioritymaintaining unit 125.

The power controlling unit 140 includes: a power activating unit 141;and a power stopping unit 142.

Also, the management server 190 includes: a monitoring unit 160 for aserver blade operation status; a judging unit 150; and anoperation-information notifying unit 170.

The monitoring unit 160 for the server blade operation status includes:a monitoring unit 161 for server blade processing amount for monitoringprocessing amounts of the server blades 130 to 132; a measuring unit 162for the number of times of activation/stop for counting the number oftimes of activation/stop of the server blades 130 to 132; and anoperation-time measuring unit 163 for measuring a total operation timeof the server blades 130 to 132.

The judging unit 150 includes: a judgment table 151; a maintaining unit152 for a power activation threshold; a maintaining unit 153 for a powerstop threshold; a maintaining unit 154 for the maximum number ofstand-by server blades; a maintaining unit 155 for the minimum number ofstand-by server blades; and a maintaining unit 156 for the minimumnumber of operating server blades.

In an example illustrated in FIG. 1, the server blade includes threeserver blades 130 to 132. However, the number of server blades is notlimited to three, and any number of server blades can be used as long asthey can be installed in the blade system 180. Also, the system may benot only one of the blade system 180 but also a plurality of connectedblade systems 180.

Each of the server blades 130 to 132 is connected to an external network110 via the load balancing blade 120, and every data communicationfrom/to the client 100 is performed via the load balancing blade 120.

Also, in the load balancing blade 120, FIG. 1 illustrates an examplethat one load balancing blade 120 is installed. However, the number ofload balancing blades is not limited to one. For example, two loadbalancing blades 120 may be installed in the blade system 180.

This case is that, for example, two load balancing blades 120 areconfigured as a redundant structure in which a stand-by load balancingblade for taking over the processing of a currently-operating loadbalancing blade is provided. In this case, even when thecurrently-operating load balancing blade is broken, the processing canbe continued by switching the processing to the stand-by load balancingblade.

In the load balancing blade 120, a packet of the request from the client100 is not directly transferred to the server blades 130 to 132, butreceived by the data-request receiving unit 121 once and transferred toany of the server blades 130 to 132 by the data-request transferringunit 122.

Also, in the server-blade monitoring unit 123, a processing status (aprocessing amount for the request from the client, the number of timesof activation/stop, and a total operation time) of each of the serverblades 130 to 132 is monitored.

The monitoring information in the server-blade monitoring unit 123 canbe shared with the monitoring unit 160 for the server blade operationstatus included in the management server 190 which is mutually connectedwith the load balancing blade 120.

Further, in the maintaining unit 124 for the load balance threshold, aload balance threshold “A” transferred by the judging unit 150 ismaintained. The load balance threshold A is a threshold used forstarting the assignment of the request from the client 100. In the loadbalance, the processing amount assigned to the server blades 130 to 132does not exceed the load balance threshold A every time, and, if itexceeds, the processing amount is assigned to a new operating serverblade. This excess can be judged by the load balancing blade 120 itselfwhich maintains the load balance threshold.

When the assigned processing proceeds to generate a margin of theprocessing amount in each of the server blades 130 to 132, a newprocessing from the client is assigned to a corresponding server bladeby the load balancing blade 120 in accordance with a priority maintainedin the priority maintaining unit 125.

That is, the request from the client can be always led to a server bladehaving a higher priority.

Also, the monitoring unit 160 for the server blade operation status inthe management server 190 can share the server blade operationinformation acquired by the load balancing blade 120, and the acquiredinformation can remain in the management server 190 as a history.

In the example illustrated in FIG. 1, the server blades 130 to 132 aremonitored by the load balancing blade 120. However, a mode in which theserver blades 130 to 132 are directly monitored by the monitoring unit160 for the server blade operation status, or a mode in which they aremonitored via a control unit installable in the blade system 180 may beused.

Further, the operation information acquired by the monitoring unit 160for the server blade operation status is transferred to the judging unit150 via the operation-information notifying unit 170.

the judging unit 150 in the management server 190 controls the poweractivation/stop, changes the priority, controls the thresholds, andcontrols the number of the operating server blades based on theoperation information transferred from the monitoring unit 160 for theserver blade operation status.

The priority is determined by the judgment table 151, and isperiodically changed and is put in accordance with the total operationtime or the number of times of the power activation/stop.

The status information of the server blade configuring the blade system180 which is determined by the judgment table 151 can be transferredfrom the management server 190 to the load balancing blade 120. The loadbalancing blade 120 can recognize the transferred information from themanagement server 190, and can judge the information for a subsequentassignment of the request from the client 100 by itself.

The judging unit 150 maintains three types of thresholds which includes:a load balance threshold “A” used for assigning the processing to thestand-by server blade previously power-activated; a power activationthreshold “B” used for activating the power of the stopping serverblade; and a power stop threshold “C” used for stopping the power of theoperating server blade. In the load balance, the processing amountassigned to the server blade does not exceed the load balance thresholdA every time, and if it exceeds, the processing is assigned to a newoperating server blade.

Here, the power stop threshold C is set to be smaller than the poweractivation threshold B. In the case of the repetitive increase anddecrease in the request from the client 100 within the narrow range,even when the request from the client 100 is decreased and theprocessing amount is lowered than the power activation threshold B rightafter the processing amount exceeds the power activation threshold B,the sufficient decrease in the request from the client is furtherrequired as low as the power stop threshold C, and therefore, it can beavoided that the switching between the power activation and stop isfrequently caused in a part of server blades.

Also, these thresholds can be freely set by a user in accordance withthe usage of the system or change of the processing amount.

Here, the processing amount of each of the server blades 130 to 132 forthe request from the client 100 monitored by the server-blade monitoringunit 123, the load balance threshold, the power activation threshold,and the power stop threshold maintained by the judging unit 150 aredescribed.

In the present embodiment, for the above-described items, the followingcomponents can be exemplified.

For example, the components include: the number of simultaneousconnections representing the number of requests from the client 100which are processed by each of the server blades 130 to 132; the numberof requested processing per unit time which is processed by each of theserver blades 130 to 132; a response time of each of the server blades130 to 132 for the request from the client 100; a processing-amount ratevalue which can be expressed by a ratio of the maximum processing volumeof each of the server blades 130 to 132; a processing-amount fix valueset in each of all server blades (except for the load balancing blade)configuring the blade system 180; and others.

For the control of the power activation/stop outputted from the judgingunit 150, a signal of the control of the power activation/stop outputtedfrom the management server 190 by, for example, LAN communication isreceived by the power controlling unit 140 in the blade system 180.

Here, inside the server blades 130 to 132, processors each calledbaseboard management controller (hereinafter, referred to as BMC) 133 to135 which are control devices for the respective server blades areembedded.

The BMCs 133 to 135 communicate with each managing/managed device on amotherboard/chassis, does not depend on a CPU (Central Processing Unit),an OS (Operating System), and BIOS (Basic Input/Output System), and cancontrol the system even from the status of the power stop.

In the blade system 180, the control of the power activation/stop isoutputted from the power controlling unit 140 to each of the BMCs 133 to135 embedded in an objective server blade by a communication method inconformity with Intelligent Platform Management Interface (hereinafter,referred to as IPMI) standard.

Here, the IPMI is a standard interface specification for monitoring,recovering, and remote-controlling states (temperature, voltage, fan,and bus) of a platform such as a server, and is known as a conventionaltechnique.

Note that the control is performed by the communication method based onthe IPMI as the example in the present embodiment. However, the methodis not limited to this.

Here, inside the power controlling unit 140, the power activating unit141 instructs the activation to the server blades 130 to 132 at thepower activation, and the power stopping unit 142 instructs the stop tothe server blades 130 to 132 at the power stop.

Next, with reference to FIGS. 2 to 4, the selection processing for theactivated/stopped server blade of the computer system according to theembodiment of the present invention is described. FIG. 2 is a diagramillustrating an example of the judgment table used in the selectionprocessing for the activated/stopped server blade of the computer systemaccording to the embodiment of the present invention, FIGS. 3 and 4 areflowcharts each illustrating the selection processing for theactivated/stopped server blade of the computer system according to theembodiment of the present invention, FIG. 3 illustrates a processingwith using each threshold in the judging unit 150 as a judgment factor,and FIG. 4 illustrates a processing with using the number of stand-byserver blades in the judging unit 150 as the judgment factor.

As illustrated in FIG. 2, the judgment table 151 includes items of aserver blade number 201, a priority 202, a status 203, a processingamount 204, the number of times of activation/stop 205, and a totaloperation time 206.

As the server blade number 201, the judgment table maintains a numbercorresponding to a location where each of the server blades 130 to 132is configured.

As the priority 202, the judgment table maintains a priorityrepresenting a priority order for assigning the request from the client100 arbitrarily set in each of the server blades 130 to 132. Also, thepriority is maintained in the load balancing blade 120 itself as well,and is used when the processing is practically assigned.

The status 203 represents a status of the server blade configuring theblade system 180. A status thereof in which the activation has beencompleted and the request from the client can be processed is set to“operating”, a status thereof after receiving the instruction of thepower activation and in the middle of the power activation is set to“activation processing”, and a status thereof in which the power is notactivated and the request from the client cannot be processed is set to“stopping”.

As the processing amount 204, the judgment table maintains the requestedamount from the client processed by each of the server blades 130 to 132at an update of the judgment table 151.

As the total operation time 206, the judgment table maintains a totaltime of the continuous operation until the update of the judgment table151.

As the number of times of activation/stop 205, the judgment tablemaintains the total number of times of switching counted in eachswitching between the activation and stop of each of the server blades130 to 132 until the update of the judgment table 151.

Note that the example in FIG. 2 illustrates the judgment table 151 in acase of nine server blades configuring the blade system 180 for theexplanation. However, the number of server blades is not limited tonine, and it may be the same as the number of server blades which can beconfigured in the blade system 180.

First, in the selection processing for the activated/stopped serverblade with using each threshold information in the judging unit 150 asthe judgment factor, as illustrated in FIG. 3, for judging the magnituderelations between a processing amount for the request from the client100 and the power activation threshold B and between a processing amountand the power stop threshold C maintained in the respectivepower-activation-threshold maintaining unit 152 and thepower-stop-threshold maintaining unit 153 included in the judging unit150, the selection processing for the activated/stopped server blade isstarted (step 300).

And, as the status 203 of the judgment table 151, it is confirmedwhether the “activation processing” server blade exists or not (step301).

If the “activation processing” server blade exists in the step 301, asthe status 203 of the judgment table 151, it is confirmed whether theactivation of the “activation processing” server blade has beencompleted or not (step 302).

If the activation of the server blade has not been completed yet in thestep 302 and the activation-processing server blade still exists, theprocessing is ended.

If the activation of the server blade has been completed in the step302, the status 203 of the corresponding server blade of the judgmenttable 151 is updated into the “operating” in order to change the statusinto the “operating” (step 303).

And, the processing amount (=X) of the operating server blade having thelowest priority among the server blades whose status 203 of the judgmenttable 151 is the “operating” is acquired (step 304).

Further, if the “activation processing” server blade does not exist inthe step 301, the processing proceeds to the step 304.

The magnitude relation between the power activation threshold (=B) andthe processing amount (=X) acquired in the step 304 is compared witheach other (step 305).

If it is judged that X is larger than 0 and equal to or smaller than Bin the step 305, it means that the processing is required with certainprocessing amount and there is no sufficient processing amount for theactivation of other server blades, and therefore, the processing isended.

If it is judged that X is larger than B in the step 305, it means thatthe processing amount for the activation of other server blades exceedsthe power activation threshold, and therefore, it is determined that theserver blade having the highest priority among the stopping serverblades is activated, the activation of the corresponding server blade iscontrolled, and the status of the judgment table 151 is updated into the“activation processing” (step 306) because the status of thecorresponding server blade enters into the stage of the power activationprocessing in accordance with the activation control.

If it is judged that “X=0” in the step 305, it means that a server bladewhose current processing amount is 0 exists, and therefore, the numberof operating server blades in the blade system is confirmed, and iscompared with the minimum number (=N) of operating server bladesmaintained in the maintaining unit 156 for the minimum number ofoperating server blades (step 307).

If a relation of “the number of operating server blades=the minimumnumber (=N) of operating server blades” is established in the step 307,the operating server blades cannot be stopped any more, and therefore,the processing is ended.

If a relation of “the number of operating server blades≠the minimumnumber (=N) of operating server blades” is confirmed in the step 307,that is, if the number of currently-operating server blades is largerthan the minimum number (=N) of operating server blades because of nopossibility that it is equal to or smaller than the minimum number (=N)of operating server blades, the processing-amount information (=Y) ofthe server blade having the second lowest priority among the operatingserver blades is acquired (step 308).

And, the magnitude relation between the acquired processing amount (=Y)and the power stop threshold (=C) is compared with each other (step309).

If it is judged that Y is equal to or larger than C in the step 309, theprocessing is ended because, when the processing amount is increasedlater in the server blade having the second lowest priority, there is apossibility that the processing is assigned to the server blade havingthe lowest priority.

If it is judged that Y is smaller than C in the step 309, it isdetermined that the server blade having the lowest priority among theoperating server blades is stopped, the stop of the corresponding serverblade is controlled, and the status of the judgment table is updatedinto the “stopping” (step 310) because the status of the correspondingserver blade enters into the stage of the power stop processing inaccordance with the stop control.

Further, in the selection processing for the activated/stopped serverblade with using each set number of server blades in the judging unit150 as the judgment factor, as illustrated in FIG. 4, for judging themagnitude relation between the number of stand-by server blades and themaximum number “L” of stand-by server blades and between the number ofstand-by server blades and the minimum number “M” of stand-by serverblades maintained in the respective maintaining unit 154 for the maximumnumber of stand-by server blades and the maintaining unit 155 for theminimum number of stand-by server blades included in the judging unit150, the selection processing for the activated/stopped server blade isstarted (step 400).

And, as the status 203 of the judgment table 151, it is confirmedwhether the “activation processing” server blade exists or not (step401).

If the “activation processing” server blade exists in the step 401, asthe status 203 of the judgment table 151, it is confirmed whether theactivation of the “activation processing” server blade has beencompleted or not (step 402).

If the activation of the server blade has not been completed yet in thestep 402 and the “activation processing” server blade still exists, theprocessing is ended.

If the activation of the server blade has been completed in the step402, the status 203 of the corresponding server blade of the judgmenttable 151 is updated into the “operating” in order to change the statusinto the “operating” (step 403).

And, the number of operating server blades (=Z) having the processingamount of 0 among the server blades whose status 203 of the judgmenttable 151 is the “operating” is acquired (step 404).

Further, if the “activation processing” server blade does not exist inthe step 401, the processing proceeds to the step 404.

The magnitude relations between the number of operating server blades(=Z) acquired in the step 404 and the maximum number of stand-by serverblades (=L) and between the number of operating server blades and theminimum number of stand-by server blades (=M) are compared with eachother (step 405).

If it is judged that Z is larger than M and equal to or smaller than Lin the step 405, it means that the number of stand-by server blades iswithin a range of an appropriate number, and therefore, the processingis ended.

If it is judged that Z is larger than L in the step 405, it means thatthe number of server blades having the processing amount of 0 is large,and therefore, it is determined that the server blade having the lowestpriority among the operating server blades is stopped, the stop of thecorresponding server blade is controlled, and the status of the judgmenttable is updated into the “stopping” (step 406) because the status ofthe corresponding server blade enters into the stage of the power stopprocessing in accordance with the stop control.

If it is judged that Z is equal to or smaller than M in the step 405, itmeans that the number of server blades having the processing amount of 0is small, and therefore, it is determined that the server blade havingthe highest priority among the stopping server blades is activated, theactivation of the corresponding server blade is controlled, and thestatus of the judgment table is updated into the “activation processing”(step 407) because the status of the corresponding server blade entersinto the stage of the power activation processing in accordance with theactivation control.

Next, a start timing of the judgment flow in FIGS. 3 and 4 and theupdate of the judgment table illustrated in FIG. 2 are described.

In the judgment flow in FIGS. 3 and 4, the judgment may be repeatedevery input of the request from the client 100 or may be periodicallyperformed with time interval by which the processing can be smoothlyperformed as considering the usage of the system or others. Also, thetiming may be freely set by a user.

Further, the judgment table 151 may be updated at timing insynchronization with the start timing or end timing of the judgment flowin FIGS. 3 and 4, or may be updated at not the timing in synchronizationwith the start timing of the judgment flow but a previously-set timingsimilarly to the start of the judgment flow. These setting tools can beeasily installed by a software or others.

Next, with reference to FIGS. 5 to 7, the change of the priority of thecomputer system according to the embodiment of the present invention isdescribed. FIGS. 5 to 7 are explanatory diagrams for explaining thechange of the priority of the computer system according to theembodiment of the present invention. Here, the conditions of the numberof the activated/stopped server blade, the processing amount, and othersare the same as those of the example illustrated in FIG. 2.

First, when the priority set in each server blade is periodicallychanged, as illustrated in FIG. 5, a priority 202 of a server bladenumber #0 in the judgment table 151 illustrated in FIG. 2 is slid into apriority of a server blade number #3 to slide an operated server bladeinto a server blade having a large server blade number by three blades.

In a case of not assuming large variation in the processing amount asthe usage of the system, by setting the periodic automatic or manualchange of the priority 202, the unbalance among the operating serverblade can be easily avoided. Also, for the timing of the change, variousschedules such as daily change and weekly change can be set.

Further, when the unbalance among the number of times of activation/stopis avoided by setting the priority 202 of the server blade having thesmaller number of times of activation/stop 205 among the stopping serverblades to higher and setting the priority 202 of the server blade havingthe larger number of times of activation/stop 205 among the operatingserver blades to lower, as illustrated in FIG. 6, first, the priority202 of the server blade having the larger number of times ofactivation/stop 205 among the operating server blades (#1, #2, #4, #5,#6, and #7) in the judgment table 151 is set to higher.

Contrarily, the priority 202 of the server blade having the smallernumber of times of activation/stop 205 among the stopping server blades(#0, #3, and #8) therein is set to higher.

Therefore, the priority 202 of the server blade having the smallernumber of times of activation/stop 205 among the operating server bladesis set to lower, and thus, the power is stopped preferentially to theserver blade having the smaller number of times of activation/stop 205among the operating server blades. Further, the priority 202 of theserver blade having the smaller number of times of activation/stop 205among the stopping server blades is set to higher, and thus, the poweris activated preferentially to the server blade having the smallernumber of times of activation/stop 205 among the stopping server blades.Therefore, the unbalance among the number of times of activation/stopcan be avoided.

The number of times of activation/stop of the server blade relates to alife of the server blade, and therefore, unbalance among the life of theserver blades can be avoided by avoiding the unbalance among the numberof times of activation/stop.

Still further, when the unbalance among the operation time is avoided bysetting a priority of a server blade having a shorter total operationtime to higher, as illustrated in FIG. 7, the priority 202 of the serverblade having the shorter total operation time 206 is set to higher.

For example, the total operation time of the server blade number #3 is33 [min] which is the shortest among those of the configuring serverblades. Therefore, its priority is set to 9, and it becomes a serverblade to which the processing is most preferentially assigned.

Therefore, regardless of the stopping and operating statuses in serverblades, the priority 202 of the server blade having the shorter totaloperation time is set to higher, and thus, the server blade having theshort total operation time is preferentially activated if it isstopping, or the processing is preferentially assigned to the serverblade if it is operating, so that the unbalance among their totaloperation time can be avoided.

In the foregoing, the invention made by the inventors of the presentinvention has been concretely described based on the embodiments.However, it is needless to say that the present invention is not limitedto the foregoing embodiments and various modifications and alterationscan be made within the scope of the present invention.

For example, in the present embodiment, the computer system has theconfiguration illustrated in FIG. 1. However, the configuration is notlimited to this, and the present invention can be used even in thefollowing configurations.

In the server blades 130 to 132, their configurations are the serverblades embedded in the blade system 180. However, their configurationsare not necessarily as the server blades, and they may be individualdifferent computers.

Also, in the blade system 180, the load balancing blade 120 and thepower controlling unit 140 are embedded. However, they are notnecessarily as embedded in the blade system 180, and may be externalindividual devices outside the blade system 180.

Further, the management server 190 is configured outside the bladesystem 180. However, it is not necessarily as configured outside, and itmay be one blade embedded in the blade system 180.

Still further, in the management server 190, the monitoring unit 160 forthe server blade operation status, the operation-information notifyingunit 170, and the judging unit 150 are configured inside the managementserver 190. However, they are not necessarily as configured inside themanagement server 190, and may be individual different devices.

Still further, in the computer system, the server blades 130 to 132 mayexist as virtual server blades, that is, virtual server blades logicallydivided on a physical server blade.

Note that, in a case that the other virtual server blade on the samephysical server blade is operated when one server blade is stopped, thepower of the corresponding physical server blade cannot be stopped, andtherefore, the power consumption of the blade system 180 cannot besignificantly reduced.

However, if the virtual server blade can be rearranged in a space of adifferent physical server blade from the corresponding physical serverblade, by providing a physical server blade of not processing therequest from the client to lower the power of the corresponding physicalserver blade, the power consumption of the blade system 180 can besuppressed.

Still further, in the load balance threshold and the power activationthreshold maintained in the judging unit 150, by providing a thresholdsetting tool on the management server 190 or the control units or othersinside the server blades 130 to 132 which can instruct to the loadbalancing blade 120, each preferable threshold can be set by a user own.

For example, a case of a ticket selling site or others as the usage ofthe system is considered, in which requests from users are concentratedto the system at one moment, and load to the system is rapidlyincreased.

In this case, if a margin can be provided between the power activationthreshold for activating the stopping server blade and the load balancethreshold for starting the assignment of the requests from the users,when the rapidly-increased requests from the users exceed the loadbalance threshold of the system, the power activation of an additionalserver blade could have been already completed without the influence ofthe operation, and the request can be assigned to the server blade, sothat a system in which data supply to the users is not delayed can beachieved.

Still further, in a case of embedding an EEPROM in each server blade,the EEPROM being called field replacement unit (hereinafter, referred toas FRU) in which, for example, a manufacturer or a serial number isstored, a power consumption value of each server blade can be set andstored in the corresponding FRU at manufacturing a device.

In this case, similarly to the present embodiment, by recognizing thepower consumption value by the server-blade monitoring unit 123, addingthe value as the judgment condition maintained in the judging unit 150,and setting a priority of a server blade having smaller powerconsumption to higher, power saving effect can be obtained.

INDUSTRIAL APPLICABILITY

The present invention relates to a computer system including: amanagement server; and a blade system including a plurality of serverblades. The computer system is mounted on a load balancing blade whichcan be mounted inside a blade system, a load balancer which is mountedoutside the blade system and is connected to the blade system or a groupof individual computers so as to provide a load balancing function toeach server blade or the group of computers, or others, and the computersystem can be used as a part of a server system.

The invention claimed is:
 1. A computer system comprising a blade systemand a management server, the blade system comprising: a plurality ofserver blades configured to process a request from a client; a powercontrolling unit configured to provide an instruction for activation andstopping of each of the plurality of server blades; a prioritymaintaining unit configured to maintain a priority of each of theplurality of server blades; and a load balancing blade configured toassign a processing of the request from the client preferentially withrespect to an operating one of the server blades having a high priorityrather than an operating one of the server blades having a low priority,and the management server comprising: a monitoring unit configured toacquire a number of times of activation/stop and a processing amount ofeach of the plurality of server blades from the blade system; a judgmenttable for storing the number of times of activation/stop and theprocessing amount of each of the plurality of server blades; and ajudging unit configured to maintain a power activation threshold, set afirst one of the server blades, which is operating and which has asmallest number of times of activation/stop among a plurality ofoperating server blades, to have a lowest priority among the pluralityof operating server blades, set a second one of the server blades, whichis stopping and which has a smallest number of times of activation/stopamong a plurality of stopping server blades, to have a highest priorityamong the plurality of stopping server blades, and control the powercontrolling unit so as to activate the second server blade having thehighest priority among the plurality of stopping server blades when afirst processing amount of the first server blade is larger than thepower activation threshold.
 2. The computer system according to claim 1,wherein the judgment table is configured to maintain the priority, andthe judging unit is configured to activate a server blade having thehighest priority among the plurality of stopping server blades when therequest from the client is increased, and to stop a server blade havingthe lowest priority among the plurality of operating server blades whenthe request from the client is decreased.
 3. The computer systemaccording to claim 2, wherein a load balance threshold is larger thanthe power activation threshold, and the power activation threshold islarger than a power stop threshold, and the judging unit is configuredto control providing of a stand-by server blade which is operating butto which the processing of the request is not assigned by the loadbalancing blade, based on information from the judgment table, the poweractivation threshold, and the power stop threshold.
 4. The computersystem according to claim 3, wherein the judging unit is configured toinclude: a first maintaining unit configured to maintain a maximumnumber of stand-by server blades; and a second maintaining unitconfigured to maintain a minimum number of stand-by server blades, andwherein the judging unit is configured to control the number of stand-byserver blades based on the maximum number of stand-by server blades andthe minimum number of stand-by server blades.
 5. The computer systemaccording to claim 4, wherein the judging unit is further configured toinclude: a maintaining unit configured to maintain a minimum number ofoperating server blades, and wherein the judging unit is configured tocontrol the number of stand-by server blades based on the minimum numberof operating server blades, the maximum number of stand-by serverblades, and the minimum number of stand-by server blades.
 6. Thecomputer system according to claim 1, wherein the management server isconfigured to periodically change the priority.
 7. The computer systemaccording to claim 6, wherein the management server is configured to seta priority of a server blade having a shorter total operation time amongthe plurality of server blades so as to be higher.